1. Field of the Invention
The present invention relates to a heat-sensitive recording material using an electron-donating dye precursor contained in microcapsules and to a developer.
2. Description of the Related Art
Heat-sensitive recording has developed in recent years because recording apparatus therefor are simple, highly reliable, and maintenance-free. Heat-sensitive recording materials that utilize the reaction between an electron-donating achromic dye and an electron-receiving compound, and heat-sensitive recording materials that utilize the reaction between a diazo salt compound and a coupler, are widely known. Extensive research has been conducted in recent years with respect to improving properties of heat-sensitive recording materials, such as (1) color development density and color development sensitivity and (2) chromogenic fastness. However, heat-sensitive recording materials have several drawbacks in terms of storage stability (resistance to heat and to light) in image areas and in non-image areas. Although various methods have been proposed to improve storage stability in image areas and in non-image areas, it is not always the case that sufficient effects are obtained.